Seal assemblies for surgical access assemblies

ABSTRACT

Access assemblies includes an instrument valve housing and a valve assembly disposed within the cavity of the instrument valve housing. The valve assembly includes a guard assembly, and a seal assembly disposed distal of the guard assembly. In embodiments, the seal assembly includes a plurality of seal segments in an overlapping configuration. Each seal segment of the plurality of seal segments includes a seal portion having a smooth surface and a ribbed surface. The ribbed surfaces include a plurality of ribs extending in a radial direction.

FIELD

The present disclosure relates to surgical access assemblies forminimally invasive surgery. More particularly, the present disclosurerelates to valve assemblies for surgical access assemblies.

BACKGROUND

In order to facilitate minimally invasive surgery, a working space mustbe created in a desired surgical site. An insufflation fluid, typicallyCO₂, is introduced into the abdomen of the patient to create an inflatedstate called a pneumoperitoneum. Surgical access assemblies are utilizedto allow the introduction of surgical instrumentation and endoscopes (orother visualization tools). These surgical access assemblies maintainthe pressure for the pneumoperitoneum, as they have one or more sealsthat adapt to the surgical instrumentation. Typically, a “zero-seal” inthe surgical access assembly seals the surgical access assembly in theabsence of a surgical instrument in the surgical access assembly, and aninstrument seal seals around a surgical instrument that has beeninserted through the surgical access assembly.

The breadth of surgical instrumentation on the market today requires arobust instrument seal capable adjusting to multiple sizes andwithstanding multiple insertions and removals of surgicalinstrumentation. Some of the instrumentation can include sharp edgesthat can tear or otherwise damage instrument seals. Therefore, it wouldbe beneficial to have a surgical access assembly with improvedinstrument seal durability.

SUMMARY

An access assembly includes an instrument valve housing, and a valveassembly disposed within the cavity of the instrument valve housing. Theinstrument valve housing including upper, lower, and inner housingsections and defining a cavity. The valve assembly includes a guardassembly, and a seal assembly disposed distal of the guard assembly. Theseal assembly includes a plurality of seal segments in an overlappingconfiguration. Each seal segment of the plurality of seal segmentsincludes a seal portion having a smooth surface and a ribbed surface.The ribbed surfaces include a plurality of ribs extending in a radialdirection.

In embodiments, the seal assembly includes a ring portion and first,second, third and fourth seal segments. The first, second, third, andfourth seal segments may be secured to the ring portion by connectorportions. The connector portions may be living hinges. The smoothsurfaces of the first, second, third, and fourth seal segments may facedistally. The ribbed surfaces of the first, second, third, and fourthseal segments may face proximally. The smooth surfaces and the ribbedsurfaces may alternate. The first seal segment may include a tab tofacilitate assembly of the seal assembly. The plurality of seal segmentsmay form a non-continuous inner seal circumference. The valve assemblymay further include a centering mechanism for biasing the valve assemblytoward a center of the cavity of the instrument valve housing.

A valve assembly includes a guard assembly and a seal assembly disposeddistal of the guard assembly. The seal assembly includes a plurality ofseal segments in an overlapping configuration. Each seal segment of theplurality of seal segments may include a seal portion having a smoothsurface and a ribbed surface. The ribbed surfaces may include aplurality of ribs extending in a radial direction.

In embodiments, the seal assembly includes a ring portion and first,second, third and fourth seal segments. The first, second, third, andfourth seal segments are secured to the ring portion by connectorportions. The connector portions may be living hinges. The smoothsurfaces of the first, second, third, and fourth seal segments may facein a distal direction. The ribbed surfaces of the first, second, third,and fourth seal segments may face in a proximal direction. The smoothsurfaces and the ribbed surface may alternate. The first seal segmentmay include a tab to facilitate assembly of the seal assembly. Theplurality of seal segments may form a non-continuous inner sealcircumference.

A seal assembly includes a ring portion, and a plurality of sealsegments extending from the ring portion in an overlappingconfiguration. Each seal segment of the plurality of seal segmentsincludes a seal portion having a smooth surface and a ribbed surface.The ribbed surfaces may include a plurality of ribs extending in aradial direction.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the disclosureand, together with a general description of the disclosure given above,and the detailed description of the embodiments given below, serve toexplain the principles of the disclosure, wherein:

FIG. 1 is a side perspective view of a surgical access assemblyaccording to an embodiment of the present disclosure;

FIG. 2 a side cross-sectional view of the surgical access assembly shownin FIG. 1 taken along section line 2-2;

FIG. 3 is an exploded perspective view of a valve assembly, with partsseparated, including a centering mechanism, a guard assembly, a sealassembly, and a retainer assembly;

FIG. 4 is a top perspective view of the seal assembly shown in FIG. 3;

FIG. 5 is a perspective view of the seal assembly shown in FIG. 4, in aninitial or unfolded condition;

FIG. 6 is a side cross-sectional view of the seal assembly shown in FIG.4 taken along section line 6-6 in FIG. 9;

FIG. 7 is an enlarged view of the indicated area of detail shown in FIG.6;

FIG. 8 is a side cross-sectional view of the seal assembly shown in FIG.4 taken along section line 8-8 in FIG. 4;

FIG. 9 is a bottom perspective view of the seal assembly shown in FIG.4, in the initial or unfolded condition;

FIG. 10 is a top perspective view of the seal assembly shown in FIG. 4,in a partially folded condition;

FIG. 11 is a top perspective view of the seal assembly shown in FIG. 4,in fully folded condition;

FIG. 12 is a bottom perspective view of the seal assembly shown in FIG.3; and

FIG. 13 is a side cross-sectional view of the valve assembly shown inFIG. 3 taken along section line 13-13 in FIG. 12.

DETAILED DESCRIPTION

Particular embodiments of the present disclosure are describedhereinbelow with reference to the accompanying drawings; however, it isto be understood that the disclosed embodiments are merely exemplary ofthe disclosure and may be embodied in various forms. Well-knownfunctions or constructions are not described in detail to avoidobscuring the present disclosure in unnecessary detail. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a basis for the claims and asa representative basis for teaching one skilled in the art to variouslyemploy the present disclosure in virtually any appropriately detailedstructure. Like reference numerals refer to similar or identicalelements throughout the description of the figures.

As used herein, the term “distal” refers to that portion of theinstrument, or component thereof which is farther from the user whilethe term “proximal” refers to that portion of the instrument orcomponent thereof which is closer to the user. As used herein, the term“about” means that the numerical value is approximate and smallvariations would not significantly affect the practice of the disclosedembodiments. Where a numerical limitation is used, unless indicatedotherwise by the context, “about” means the numerical value can vary by±10% and remain within the scope of the disclosed embodiments.

Surgical access assemblies with obturators are employed during minimallyinvasive surgery, e.g., laparoscopic surgery, and provide for the sealedaccess of surgical instruments into an insufflated body cavity, such asthe abdominal cavity. The surgical access assemblies of the presentdisclosure include an instrument valve housing mounted on a cannulatube, and include an obturator (not shown) inserted through the valvehousing and cannula. The obturator can have a blunt distal end, or abladed or non-bladed penetrating distal end and can be used to incisethe abdominal wall so that the surgical access assembly can beintroduced into the abdomen. The handle of the obturator can engage orselectively lock into the instrument valve housing of the surgicalaccess assembly.

Surgical access assemblies are employed to tunnel through an anatomicalstructure, e.g., the abdominal wall, either by making a new passagethrough the anatomical structure or by passing through an existingopening through the anatomical structure. Once the surgical accessassembly with the obturator has tunneled through the anatomicalstructure, the obturator is removed, leaving the surgical accessassembly in place. The instrument valve housing of the surgical accessassembly includes valves that prevent the escape of insufflation fluidfrom the body cavity, while also allowing surgical instruments to beinserted into the body cavity.

In various embodiments, a bladeless optical trocar obturator may beprovided that permits separation of tissue planes in a surgicalprocedure and visualization of body tissue fibers as they are beingseparated, thereby permitting a controlled traversal across a body wall.In other embodiments, the trocar obturator may be bladeless withoutbeing optical, e.g., without providing contemporaneous visualizationthereof through the distal tip of an obturator. The bladeless obturatormay be provided for the blunt dissection of the abdominal lining duringa surgical procedure.

Various trocar obturators suitable for use with the surgical accessassembly of the present disclosure are known and include, for example,bladed, bladeless, blunt, optical, and non-optical. For a detaileddescription of the structure and function of exemplary trocarassemblies, including exemplar trocar obturators and exemplar cannulas,please refer to PCT Publication No. WO 2016/186905 (“the '905publication”), the content of which is hereby incorporated by referenceherein in its entirety.

With initial reference now to FIG. 1, a surgical access assemblyaccording to aspects of the present disclosure is shown generally assurgical access assembly 100. The surgical access assembly 100 includesa cannula 102 and an instrument valve housing 110 secured to the cannula102. For a detailed description of an exemplary surgical accessassembly, please refer to the '905 publication.

With reference to FIG. 2, the instrument valve housing 110 of thesurgical access assembly 100 includes an upper housing section 112, alower housing section 114, and an inner housing section 116. The upper,lower, and inner housing sections 112, 114, 116 are configured tosupport a valve assembly 120 on a proximal end of the cannula 102. Moreparticularly, the inner housing section 116 is secured between the upperand lower housing sections 112, 114, and the valve assembly 120 isreceived between the inner and lower housing sections 116, 114. Theupper and lower housing sections 112, 114 of the instrument valvehousing 110 may be selectively attachable to, and detachable from, theinner housing section 116. The lower housing section 114 may bereleasably or permanently attached to a cannula tube 104 (FIG. 1) of thecannula 102. In embodiments, either or both of the upper and lowerhousing sections 112, 114 of the instrument valve housing 110 mayinclude knurls, indentations, tabs, or be otherwise configured tofacilitate engagement by a clinician.

The surgical access assembly 100 may also include features for thestabilization of the surgical access assembly. For example, the distalend of the cannula tube 104 may carry a balloon anchor or anotherexpandable member that engages the abdomen from the interior side. Forexample, see U.S. Pat. No. 7,300,448, the entire disclosure of which ishereby incorporated by reference herein. A feature on the opposite sideof the abdominal wall may be used to further stabilize the surgicalaccess assembly, such as adhesive tabs or adjustable foam collars.

The upper, lower, and inner housing sections 112, 114, 116 of theinstrument valve housing 110 define a longitudinal passage 111 forreceipt of a surgical instrument (not shown). The valve assembly 120 issupported within the instrument valve housing 110 to provide sealedpassage of the surgical instrument (not shown) through the surgicalaccess assembly 100.

With particular reference to FIGS. 2 and 3, the valve assembly 120supported in the instrument valve housing 110 (FIG. 2) includes acentering mechanism 130, a guard assembly 140, a seal assembly 160, anda retainer assembly 190. The centering mechanism 130 of the valveassembly 120 permits radial movement of the valve assembly 120 relativeto the instrument valve housing 110 when a surgical instrument isreceived through the valve assembly 120, and returns the valve assembly120 to a generally centered position once the surgical instrument iswithdrawn from within the instrument valve housing 110. The guardassembly 140 protects the seal assembly 160 during insertion andwithdrawal of a surgical instrument through the seal assembly 160. Theseal assembly 160 provides sealed passage of the surgical instrumentthrough the instrument valve housing 110. The retainer assembly 190maintains the centering mechanism 130, the guard assembly 140, and theseal assembly 160 in an aligned relationship with one another.

With continued reference to FIGS. 2 and 3, as noted above, the centeringmechanism 130 of the valve assembly 120 is configured to maintain thevalve assembly 120 centered within the instrument valve housing 110(FIG. 2) in the absence of a surgical instrument passing through thevalve assembly 120. In embodiments, and as shown, the centeringmechanism 130 includes an outer annular ring 132, an inner annular ring134, and a bellows 136 disposed between the outer annular ring 132 andthe inner annular ring 134. As shown in FIG. 2, the outer annular ring132 is received between the inner housing section 116 and the lowerhousing section 114 to retain the centering mechanism 130 within theinstrument valve housing 110. The inner annular ring 134 supports theguard assembly 140. For a detailed description of the structure andfunction of an exemplary centering mechanism, please refer to U.S. Pat.No. 6,702,787, the content of which is incorporated herein by referencein its entirety.

Although shown including the centering mechanism 130 having bellows 136,the valve assembly 120 may include alternative centering mechanisms. Forexample, the centering mechanism may include an annular base and aplurality of spokes extending from the base, as described in U.S. Pat.App. Pub. No. 2015/0025477 (“the '477 publication”), the content ofwhich is incorporated herein by reference in its entirety. It isenvisioned that the centering mechanism may include multiple sets ofspokes, as disclosed in the '477 publication.

With continued reference to FIGS. 2 and 3, the guard assembly 140 of thevalve assembly 120 is configured to protect the seal assembly 160 as asurgical instrument (not shown) passes through the instrument valvehousing 110 (FIG. 2).

The guard assembly 140 includes a ring portion 142 and first, second,third, and fourth petals 144, 146, 148, 150. The first, second, third,and fourth petals 144, 146, 148, 150 define an opening 141 therebetweento facilitate sealed passage of a surgical instrument (not shown)through the guard assembly 140. Although shown including six (4) petals,it is envisioned that the guard assembly may include any suitable numberof petals, and the petals may include flap portions of any size orconfiguration. For exemplary guard assemblies, as well as other aspectsof surgical access assemblies, please refer to U.S. Pat. Nos. 5,895,377and 6,569,120 (“the '377 and '120 patents”), the entire disclosures ofwhich are hereby incorporated by reference herein. For detaileddescription of the structure and function of other exemplary guardassemblies, please refer to commonly owned U.S. Pat. App. Pub. Nos.2020/0214740A1, 2020/0337723A1, and 2021/0113240A1, the entiredisclosures of which are incorporated herein by reference in itsentirety.

Referring to FIGS. 4-6, the seal assembly 160 of the valve assembly 120is configured to provide a seal around an outer surface of a surgicalinstrument passing through the instrument valve housing 110 (FIG. 1). Inembodiments, and as shown, the seal assembly 160 forms a conical sealbody; however, it is envisioned that the aspects of the presentdisclosure may be modified for use with a flat seal body.

The seal assembly 160 includes first, second, third, and fourth sealsegments 162, 164, 166, 168 each having a base or ring portion 172, 174,176, 178, respectively, and a respective seal portion 182, 184, 186, 188supported by the respective ring portion 172, 174, 176, 178. The firstand second seal segments 162, 164, the second and third seal segments164, 166, and the third and fourth seal segments 166, 168, are connectedto one another by a connector portion 162 a, 164 a, 166 a, respectively.The connector portions 162 a, 164 a, 166 a may include a living hinge,or be otherwise configured to permit folding of the respective first,second, third, and fourth seal segments 162, 164, 166, 168 with respectto each other.

The seal portions 182, 184, 186, 188 of the respective first, second,third, and fourth seal segments 162, 164, 166, 168 of the seal assembly160 are formed of an elastic material, e.g., rubber, and define asemi-conical configuration when the seal assembly 160 is in the foldedcondition. As noted above, the seal portions 182, 184, 186, 188 mayalternatively define a flat seal. In embodiments, the seal portions 182,184, 186, 188 are formed of polyurethane, polyisoprenes, or siliconeelastomers. The ring portions 172, 174, 176, 178 of the respectivefirst, second, third, and fourth seal segments 162, 164, 166, 168 of theseal assembly 160 may be formed of the same or different materials asthe respective seal portions 182, 184, 186, 188. In embodiments, theseal portions 182, 184, 186, 188 may include one or more fabric layers.

The ring portions 172, 174, 176, 178 of the respective first, second,third, and fourth seal segments 162, 164, 166, 168 of the seal assembly160 define openings 173, 175, 177, 179, respectively, and a plurality ofopenings 173 a, 175 a, 177 a, 179 a corresponding to a plurality of pins196 (FIG. 13) extending from an upper retainer member 192 of theretainer assembly 190. In embodiments, and as shown, the ring portion172 of the first seal section 162 may include a tab 172 a to facilitateassembly and/or positioning of the seal assembly 160.

The seal portions 182, 184, 186, 188 of the respective first, second,third, and fourth seal segments 162, 164, 166, 168 of the seal assembly160 define a central opening 161 and are configured to receive asurgical instrument (not shown) through the valve assembly 120 in asealed manner. The seal portions 182, 184, 186, 188, form anon-continuous or virtual seal circumference to reduce tearing duringinsertion, manipulation, and/or withdrawal of a surgical instrument (notshown) through the valve assembly 120.

An inner edge of the seal portions 182, 184, 186, 188 of the respectivefirst, second, third, and fourth seal segments 162, 164, 166, 168 of theseal assembly 160 forms an angle “α” (FIG. 9) between about one-hundredeighty degrees (180°) and about two-hundred twenty degrees (220°). Inthis manner, each seal portion 182, 184, 186, 188 occupies at leastfifty percent (50%) of the respective opening 173, 175, 177, 179 in thering portions 172, 174, 176, 178, respectively.

With particular reference to FIGS. 5 and 9, the seal portions 182, 184,186, 188 of the respective first, second, third, and fourth sections162, 164, 166, 168 of the seal assembly 160 includes a first or ribbedsurface 182 a, 184 a, 186 a, 188 a and a second or smooth surface 182 b,184 b, 186 b, 188 b. When the seal assembly 160 is in a folded condition(FIG. 4), the ribbed surfaces 182 a, 184 a, 186 a, 188 a face proximallyand the smooth surfaces 182 b, 184 b, 186 b, 188 b face distally. Inthis manner, the smooth surfaces 182 b, 184 b, 186 b of the respectiveseal portions 182, 184, 186 of the first, second and third seal segments162, 164, 166, respectively, engage the ribbed surfaces 184 a, 186 a,188 a of the respective seal portions 184, 186, 188 of the second,third, and fourth seal segments 164, 166, 168.

The ribbed surfaces 182 a, 184 a, 186 a, 188 a of the respective sealportions 182, 184, 186, 188 of the first, second, third, and fourth sealsegments 162, 164, 166, 168, respectively, include a plurality of raisedportions or ribs 183, 185, 187, 189. Each rib 183 a, 185 a, 187 a, 189 aof the plurality of ribs 183, 185, 187, 189 extends in a radialdirection. In embodiments, and as shown in FIG. 7, each rib 183 a, 185a, 187 a, 189 a is tapered on leading and trailing portions.Alternatively, each rib 183 a, 185 a, 187 a, 189 a may have only aleading or trailing tapered portion, or instead may include a consistentthickness.

The plurality of ribs 183, 185, 187, 189 of the ribbed surface 182 a,184 a, 186 a, 188 a of the respective seal portions 182, 184, 186, 188of the first, second, third, and fourth seal segments 162, 164, 166,168, respectively, create extra padding along the ribbed surfaces 182 a,184 a, 186 a, 188 a to reduce the likelihood of tearing the sealassembly during insertion, manipulation, and/or withdrawn of a surgicalinstrument (not shown) through the seal assembly 160. The plurality ofribs 183, 185, 187, 189 are arranged such then when the seal assembly160 is in the folded condition (FIG. 4) the seal portions 182, 184, 186,188 form a seal having a increased uniform thickness. The increaseduniform thickness of the seal and/or the reinforcement provided by theplurality of ribs 183, 185, 187, 189 to the respective seal portions182, 184, 186, 188 reduces the possibility of a surgical instrument (notshown) puncturing the seal portions 182, 184, 186, 188, thereby reducingthe likelihood of tearing. This design also limits additional potentialleak paths.

The method of folding the seal assembly 160 will now be described withreference to FIGS. 9-11. Referring initially to FIG. 9, the first sealsection 162 of the seal assembly 160 is folded relative to the secondseal section 164 of the seal assembly 160, as indicated by arrow “A”,such that the smooth surface 182 b (FIG. 5) of the first seal section162 overlaps the ribbed surface 184 a (FIG. 5) of the second sealsection 164. Similarly, the fourth seal section 168 of the seal assembly160 is folded relative to the third seal section 166 of the sealassembly 160, as indicated by arrow “B”, such that the ribbed surface188 a (FIG. 5) of the fourth section 168 overlaps the smooth surface 186b (FIG. 5) of the third seal section 166.

Turning to FIG. 10, the first and second seal segments 162, 164 of theseal assembly 160 are then folded relative to the third and fourth sealsegments 166, 168 of the seal assembly 160, as indicated by arrow “C”,such that the ribbed surface 184 a (FIG. 5) of the second seal section164 overlaps the smooth surface 186 b (FIG. 5) of the third section 166.

With reference to FIGS. 12 and 13, the retainer assembly 190 (of thevalve assembly 120) is configured to secure the guard assembly 140relative to the seal assembly 160, and secure the guard and sealassemblies 140, 160 to the centering mechanism 130. The retainerassembly 190 includes an upper retainer member 192, and a lower retainermember 194.

As noted above, the upper retainer member 192 of the retainer assembly190 includes a plurality of pins 196. The plurality of pins 196 extendsfrom a bottom surface of the upper retainer member 192 (FIG. 13). Eachpin 196 of the plurality of pins 196 is configured to be lockinglyreceived within an opening 195 of a plurality of openings 195 of thelower retainer member 194. In embodiments, the plurality of pins 196 iswelded, glued, adhered, bonded or otherwise secured within the pluralityof openings 195 in the lower retainer member 194 to secure the upperretainer member 192 and the lower retainer member 194 together.Alternatively, the lower retainer member 194 may instead, oradditionally, include a plurality of pins (not shown) with the upperretainer member 192 defining a plurality corresponding openings (notshown). Either or both of the upper and lower retainer members 192, 194may include locking features (not shown) for engaging the plurality ofpins and securing the upper retainer member 192 to the lower retainermember 194.

With continued reference to FIGS. 12 and 13, the plurality of pins 196of the upper retainer member 192 extends through the ring portion 142 ofthe guard assembly 140, through the inner annular ring 134 of thecentering mechanism 130, through the seal assembly 160, and into theplurality of openings 195 in the lower retainer member 194. As notedabove, placing the guard assembly 140 proximal of the seal assembly 160reduces or eliminates potential damage to the seal assembly 160 duringinsertion and retraction of a surgical instrument through the sealassembly 160. The placement of the guard assembly 140 also reduces thepotential of the seal assembly 160 disintegrating into the body cavityduring minimally invasive procedures.

During a surgical procedure utilizing surgical access assembly 100 (FIG.1), a surgical instrument (not shown) is introduced into the instrumentvalve housing 110 through the longitudinal passage 111 in the upper,lower, and inner housing sections 112, 114, 116 (FIG. 2). As describedin the'377 and '120 patents, the distal end of the surgical instrumentengages the first, second, third, and fourth petals 144, 146, 148, 150(FIG. 3) of the guard assembly 140 causing flaps of the respectivefirst, second, third, and fourth petals 144, 146, 148, 150 to flexdownward into contact with the seal assembly 160 to cause the centralopening 161 of the seal assembly 160 to open to accommodate passage ofthe surgical instrument through the seal assembly 160. The guardassembly 140 minimizes damage to the seal assembly 160 during insertionof an instrument through the valve assembly 120

As noted above, the plurality of ribs 183, 185, 187, 189 of the ribbedsurface 182 a, 184 a, 186 a, 188 a of the respective seal portions 182,184, 186, 188 of the first, second, third, and fourth seal segments 162,164, 166, 168, respectively, create extra padding along the ribbedsurface 182 a, 184 a, 186 a, 188 a to reduce the likelihood of tearingthe seal assembly during insertion, manipulation, and/or withdrawn of asurgical instrument (not shown) through the seal assembly 160.

While various embodiments of the present disclosure have been shown anddescribed herein, it will be obvious to those skilled in the art thatthese embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the present disclosure. Accordingly,it is intended that the invention be limited only by the spirit andscope of the appended claims.

What is claimed is:
 1. An access assembly comprising: an instrumentvalve housing including upper, lower, and inner housing sections anddefining a cavity; and a valve assembly disposed within the cavity ofthe instrument valve housing, the valve assembly including: a guardassembly; a seal assembly disposed distal of the guard assembly, theseal assembly including a ring portion and a plurality of seal segmentsextending from the ring portion in an overlapping configuration, eachseal segment of the plurality of seal segments including a seal portionhaving a smooth surface and a ribbed surface, wherein the smoothsurfaces and the ribbed surfaces alternate and the ribbed surfacesinclude a plurality of ribs extending in a radial direction; and aretainer assembly securing the guard assembly relative to the sealassembly, wherein the plurality of seal segments includes four sealsegments.
 2. The access assembly of claim 1, wherein the four sealsegments are secured to the ring portion by connector portions.
 3. Theaccess assembly of claim 2, wherein the connector portions are livinghinges.
 4. The access assembly of claim 2, wherein the smooth surface ofeach of the four seal segments faces distally.
 5. The access assembly ofclaim 1, wherein the ribbed surface of each of the four seal segmentsfaces proximally.
 6. The access assembly of claim 1, wherein one of thefour seal segments includes a tab to facilitate assembly of the sealassembly.
 7. The access assembly of claim 1, wherein the plurality ofseal segments form a non-continuous inner seal circumference.
 8. Theaccess assembly of claim 1, further including a centering mechanism forbiasing the valve assembly toward a center of the cavity of theinstrument valve housing.
 9. An access assembly for receiving aninstrument through the access assembly in a sealed manner, the accessassembly comprising: a valve assembly including, a guard assembly havinga plurality of overlapping petals; and a seal assembly disposed distalof the guard assembly, the seal assembly including a plurality of ringportions and a plurality of seal segments in an overlappingconfiguration, each seal segment of the seal segment extending from eachring portion of the plurality of ring portions and folded including aseal portion having a smooth surface and a ribbed surface, wherein theribbed surfaces include a plurality of ribs extending in a radialdirection, wherein the plurality of ring portions includes more than tworing portions.
 10. The valve assembly of claim 9, wherein the sealassembly includes ring portions and first, second, third and fourth sealsegments.
 11. The valve assembly of claim 10, wherein the first, second,third, and fourth seal segments are each secured to the respective ringportion by a connector portion.
 12. The valve assembly of claim 11,wherein the connector portions are living hinges.
 13. The valve assemblyof claim 10, wherein the smooth surfaces of the first, second, third,and fourth seal segments face in a distal direction.
 14. The valveassembly of claim 10, wherein the ribbed surfaces of the first, second,third, and fourth seal segments face in a proximal direction.
 15. Thevalve assembly of claim 10, wherein the first seal segment includes atab to facilitate assembly of the seal assembly.
 16. The valve assemblyof claim 9 wherein the smooth surfaces and the ribbed surface alternate.17. The valve assembly of claim 9, wherein the plurality of sealsegments form a non-continuous inner seal circumference.
 18. A sealassembly for an access assembly for receiving an instrument through theaccess assembly in a sealed manner, the seal assembly comprising: a ringportion; and a plurality of seal segments extending from the ringportion in an overlapping configuration, each seal segment of theplurality of seal segments including a seal portion having a smoothsurface a ribbed surface, an outer portion in engagement with the ringportion, and an inner portion defining a section of an opening, theinner portions of the plurality of seal segments forming anon-continuous inner seal circumference to reduce tearing by instrumentsreceived through the seal assembly, wherein the ribbed surfaces includea plurality of elongate ribs extending from the inner portion to theouter portion, wherein the plurality of seal segments includes four sealsegments.